With a few alterations and additions it would entirely answer ourpurpose. So we bought the property.

I may mention that when I retired from business, and took out of it thefortune that had accumulated during my twenty-two years of assiduousattention and labour, I invested the bulk of it in Three per centConsols. The rate of interest was not high, but it was neverthelesssecure. High interest, as every one knows, means riskful security.I desired to have no anxiety about the source of my income, such asmight hinder my enjoying the rest of my days in the active leisurewhich I desired. I had for some time before my retirement beeninvesting in consols, which my dear wife termed "the true antibiliousstock," and I have ever since had good reason to be satisfied with thatsafe and tranquillising investment. All who value the health-conservinginfluence of the absence of financial worry will agree with me thatthis antibilious stock is about the best.

The "Cottage in Kent" was beautiful, especially in its ruralsurroundings. The view from it was charming, and embodied all theattractive elements of happy-looking English scenery. The noble oldforest trees of Penshurst Park were close alongside, and the grand oldhistoric mansion of Penshurst Place was within a quarter of a mile'sdistance from our house. There were many other beautiful parks andcountry residences in our neighbourhood; the railway station, which waswithin thirty-five minutes' pleasant walk, enabling us to be withinreach of London, with its innumerable attractions, in little more thanan hour and a quarter. Six acres of garden-ground at first surroundedour cottage, but these were afterwards expanded to sixteen; and thewhole was made beautiful by the planting of trees and shrubs over thegrounds. In all this my wife and myself took the greatest delight.

[Image] Hammerfield, Penshurst.

From my hereditary regard for hammers--two broken hammer-shafts beingthe crest of our family for hundreds of years--I named the placeHammerfield; and so it remains to this day. The improvements andadditions to the house and the grounds were considerable. A greenhousewas built, 120 feet long by 32 feet wide. Roomy apartments were addedto the house. The trees and shrubs planted about the grounds werecarefully selected. The coniferae class were my special favourites.I arranged them so that their natural variety of tints should form themost pleasing contrasts. In this respect I introduced the beech-treewith the happiest effect. It is bright green in spring, and in theautumn it retains its beautiful ruddy-tinted leaves until the end ofwinter, when they are again replaced by the new growth.

The warm tint of the beech contrasts beautifully with the bright greenof the coniferae, especially of the Lawsoniania and the Douglassi--the latter being one of the finest accessions to our list of conifers.It is graceful in form, and perfectly hardy. I also interspersed withthese several birch-trees, whose slender and graceful habit of growthforms so fine a contrast to the dense foliage of the conifers.To thus paint, as it were, with trees, is a high source of pleasure ingardening. Among my various enjoyments this has been about the greatest.

During the time that the alterations and enlargements were in progresswe rented a house for six months at Sydenham, close to the beautifulgrounds of the Crystal Palace. This was a most happy episode in ourlives, for, besides the great attractions of the place, both inside andout, there were the admirable orchestral daily concerts, at which wewere constant attendants. We had the pleasure of listening to thenoble compositions of the great masters of music, the perfectly trainedband being led by Herr Manns, who throws so much of his fine naturaltaste and enthusiastic spirit into the productions as to give themevery possible charm.

From a very early period of my life I have derived the highestenjoyment from listening to music, especially to melody, which is to methe most pleasing form of composition. When I have the opportunity oflistening to such kind of music, it yields me enjoyment that transcendsall others. It suggests ideas, and brings vividly before the mind'seye scenes that move the imagination. This is, to me, the highestorder of excellence in musical composition. I used long ago, and stillcontinue, to whistle a bit, especially when engaged in some pleasantoccupation. I can draw from my mental repository a vast number of airsand certain bits of compositions that I had once heard. I possess thatimportant qualification for a musician--"a good ear;" and I alwaysworked most successfully at a mechanical drawing when I was engaged inwhistling some favourite air. The dual occupation of the brain hadalways the best results in the quick development of the constructivefaculty. And even in circumstances where whistling is not allowed Ican think airs, and enjoy them almost as much as when they aredistinctly audible. This power of the brain, I am fain to believe,indicates the natural existence of the true musical faculty. But I hadbeen so busy during the course of my life that I had never anyopportunity of learning the practical use of any musical instrument.And here I must leave this interesting subject.

So soon as I was in due possession of my house, I had speedilytransported thither all my art treasures--my telescopes, my homestock of tools, the instruments of my own construction, made from thevery beginning of my career as a mechanic, and associated with the mostinteresting and active parts of my life. I lovingly treasured them,and gave them an honoured place in the workshop which I added to myresidence. There they are now, and I often spend a busy and delightfulhour in handling my tools. It is curious how the mere sight of suchobjects brings back to the memory bygone incidents and recollections.Friends long dead seem to start up while looking at them. You almostfeel as if you could converse with the departed. I do not know ofanything so touchingly powerful in vividly bringing back the treasuredincidents and memories of one's life as the sight of such humbleobjects. Every one has, no doubt, a treasured store of such materialrecords of a well-remembered portion of his past life. These strike,as it were, the keynote to thoughts that bring back in vivid form themost cherished remembrances of our lives. On many occasions I haveseen at sale rooms long treasured hoards of such objects throwntogether in a heap as mere rubbish. And yet these had been to some thesources of many pleasant thoughts and recollections, But the last finalbreak-up has come, and the personal belongings of some departed kindheart are scattered far and wide. These touching relics of a longlife, which had almost become part of himself, are "knocked down" tothe lowest class of bidders. It is a sad sight to witness the uncaredfor dispersion of such objects--objects that had been lovingly storedup as the most valued of personal treasures. I could have wished that,as was the practice in remote antiquity, such touching relics wereburied with the dead, as their most fitting repository. Then theymight have left some record, instead of being desecrated by the harpieswho wait at sales for such "job lots."

Behold us, then, settled down at Hammerfield for life. We had plentyto do. My workshop was fully equipped. My hobbies were there,and I could work them to my heart's content. The walls of our variousrooms were soon hung with pictures, and other works of art, suggestiveof many pleasant associations of former days. Our library book-casewas crowded with old friends, in the shape of books that had been readand re-read many times, until they had become almost part of ourselves.Old Lancashire friends made their way to us when "up in town,"and expressed themselves delighted with our pleasant house and itsbeautiful surroundings.

The continuous planting of the shrubs and trees gave us great pleasure.Those already planted had grown luxuriantly, fed by the fertile soiland the pure air. Indeed, in course of time they required thejudicious use of the axe in order to allow the fittest to survive andgrow at their own free will. Trees contrive to manage their ownaffairs without the necessity of much labour or interference.The "survival of the fittest" prevails here as elsewhere. It is alwaysa pleasure to watch them. There are many ordinary old-fashionedroadside flowering plants which I esteem for their vigorous beauty,and I enjoy seeing them assume the careless grace of Nature.

The greenhouse is also a source of pleasure, especially to my dearwife. It is full of flowers of all kinds, of which she is devotedlyfond. They supply her with subjects for her brush or her needle.She both paints them and works them by her needle in beautiful formsand groups. This is one of her many favourite hobbies. All this issuitable to our fireside employments, and makes the days and theevenings pass pleasantly away.

CHAPTER 21. Active leisure.

When James Watt retired from business towards the close of his usefuland admirable life, he spoke to his friends of occupying himself with"ingenious trifles," and of turning "some of his idle thoughts" uponthe invention of an arithmetical machine and a machine for copyingsculpture. These and other useful works occupied his attention formany years.

It was the same with myself. I had good health (which Watt had not)and abundant energy. When I retired from business I was onlyforty-eight years old, which may be considered the prime of life.But I had plenty of hobbies, perhaps the chief of which was Astronomy.No sooner had I settled at Hammerfield than I had my telescopes broughtout and mounted. The fine clear skies with which we were favoured,furnished me with abundant opportunities for the use of my instruments.I began again my investigations on the Sun and the Moon, and made someoriginal discoveries, of which more anon.

Early in the year 1858 I received a pressing invitation from theCouncil of the Edinburgh Philosophical Society to give a lecture beforetheir members on the Structure of the Lunar Surface. As the subjectwas a favourite one with me, and as I had continued my investigationsand increased my store of drawings since I had last appeared before anEdinburgh audience, I cheerfully complied with their request.I accordingly gave my lecture before a crowded meeting in theQueen Street Lecture Hall.

The audience appeared to be so earnestly interested by the subject thatI offered to appear before them on two successive evenings and give anyviva voce explanations about the drawings which those present mightdesire. This deviation from the formality of a regular lecture wasattended with the happiest results. Edinburgh always supplies ahighly-intelligent audience, and the cleverest and brightest were readywith their questions. I was thus enabled to elucidate the lecture andto expand many of the most interesting points connected with the moon'ssurface, such as might formerly have appeared obscure. These questioninglectures gave the highest satisfaction. They satisfied myself as wellas the audience, who went away filled with the most graphic informationI could give them on the subject.

But not the least interesting part of my visit to Edinburgh on thisoccasion was the renewed intercourse which I enjoyed with many of myold friends. Among these were my venerable friend Professor Pillans,Charles Maclaren (editor of the Scotsman), and Robert Chambers.We had a long dander together through the Old Town, our talk being inbroad Scotch. Pillans was one of the fine old Edinburgh Liberals,who stuck to his principles through good report and through evil.In his position as Rector of the High School, he had given rareevidence of his excellence as a classical scholar. He was afterwardspromoted to be a Professor in the University. He had as his pupilssome of the most excellent men of my time. Amongst his intimatefriends were Sydney Smith, Brougham, Jeffrey, Cockburn--men who gaveso special a character to the Edinburgh society of that time.

We had a delightful stroll through some of the most remarkable parts ofthe Old Town, with Robert Chambers as our guide. We next mountedArthur's Seat to observe some of the manifestations of volcanic action,which had given such a remarkable structure to the mountain.On this subject, Charles Maclaren was one of the best living expounders.He was an admirable geologist, and had closely observed the features ofvolcanic action round his native city. Robert Chambers then took us tosee the glacial grooved rocks on another part of the mountain.On this subject he was a master. It was a vast treat to me to seethose distinct evidences of actions so remotely separated in point ofgeological time--in respect to which even a million of years is ahumble approximate unit* [footnote..."It is to our ever-dropping climate, with its hundred and fifty-two daysof annual rain, that we owe our vegetable mould with its rich andbeauteous mantle of sward and foliage. And next, stripping from offthe landscape its sands and gravels, we see its underlying boulder-clays,dingy and gray, and here presenting their vast ice-borne stones,and there its iceberg pavements. And these clays in turn stripped away,the bare rocks appear, various in colour and uneven in surface,but everywhere grooved and polished, from the sea level and beneath it,to the height of more than a thousand feet, by evidently the same agentthat careered along the pavements and transported the great stones.

HUGH MILLER'S Geological Features of Edinburgh and its Neighbourhood. ...]

What a fine subject for a picture the group would have made! with thegreat volcanic summit of the mountain behind, the noble romantic cityin the near distance, and the animated intelligent countenaces of thedemonstrators, with the venerable Pillans eagerly listening--for theProfessor was then in his eighty-eighth year. I had the happiness ofreceiving a visit from him at Hammerfield in the following year.He was still hale and active; and although I was comparatively a boy tohim, he was as bright and clear-headed as he had been forty years before.

In the course of the same year I accompanied my wife and my sisterCharlotte on a visit to the Continent. It was their first sojourn inforeign parts. I was able, in some respects, to act as their guide.Our visit to Paris was most agreeable. During the three weeks we werethere, we visited the Louvre, the Luxembourg, Versailles, and the partsround about. We made many visits to the Hotel Cluny, and inspected itsmost interesting contents, as well as the Roman baths and that part ofthe building devoted to Roman antiquities. We were especiallydelighted with the apartments of the Archbishop of Paris, now hung withfine old tapestry and provided with authentic specimens of mediaevalfurniture. The quaint old cabinets were beautiful studies; and manyartists were at work painting them in oil. Everything was in harmony.When the sun shone in through the windows in long beams of colouredlight, illuminating portions of the antique furniture, the pictureswere perfect. We were much interested also by the chapel in whichMary Queen of Scots was married to the Dauphin. It is still in completepreservation. The Gothic details of the chapel are quite a study;and the whole of these and the contents of this interesting Museum forma school of art of the best kind.

From Paris we paid a visit to Chartres, which contains one of the mostmagnificent cathedrals in France. Its dimensions are vast,its proportions are elegant, and its painted glass is unequalled.Nothing can be more beautiful than its three rose-windows. But I amnot writing a guide-book, and I must forbear. After a few days more atParis we proceeded south, and visited Lyons, Avignon, and Nismes, onour way to Marseilles. I have already described Nismes in my previousvisit to France. I revisited the Roman amphitheatre, the Maison Quarree,that perfect Roman temple, which, standing as it does in an opensquare, is seen to full advantage. We also went to see the magnificentRoman aqueduct at Pont du Gard. The sight of the noble structure wellrepays a visit. It consists of three tiers of arches. Its magnitude,the skilful fitting of its enormous blocks, makes a powerful impressionon the mind. It has stood there, in that solitary wooded valley,for upwards of sixteen centuries; and it is still as well fitted forconveying its aqueduct of water as ever. I have seen nothing tocompare with it, even at Rome. It throws all our architectural buildingsinto the shade. On our way back from Marseilles to Paris we visitedGrenoble and its surrounding beautiful Alpine scenery.Then to Chambery, and afterwards to Chamounix, where we obtained asplendid view of Mont Blanc. We returned home by way of Geneva andParis, vastly delighted with our most enjoyable journey.

I return to another of my hobbies. I had an earnest desire to acquirethe art and mystery of practical photography. I bought the necessaryapparatus, together with the chemicals; and before long I became anexpert in the use of the positive and negative collodion process,including the printing from negatives, in all the details of thatwonderful and delightful art. To any one who has some artistic taste,photography, both in its interesting processes and glorious results,becomes a most attractive and almost engrossing pursuit. It is adelightful means of educating the eye for artistic feeling, as well asof educating the hands in delicate manipulation. I know of nothingequal to photography as a means of advancing one's knowledge in theserespects. I had long meditated a work "On the Moon," and it was forthis purpose more especially that I was earnest in endeavouring toacquire the necessary practical skill. I was soon enabled to obtainphotographic copies of the elaborate models of parts of the moon's,surface, which I had long before prepared. These copies were hailed bythe highest authorities in this special department of astronomicalresearch as the best examples of the moon's surface which had yet beenproduced.

In reference to this subject, as well as to my researches into thestructure of the sun's surface, I had the inestimable happiness ofsecuring the friendship of that noble philosopher, Sir John Herschel.His visits to me, and my visits to him, have left in my memory the mostcherished and happy recollections. Of all the scientific men I havehad the happiness of meeting, Sir John stands supremely at the head ofthe list. He combined profound knowledge with perfect humility.He was simple, earnest, and companionable, He was entirely free fromassumptions of superiority, and, still learning, would listenattentively to the humblest student. He was ready to counsel andinstruct, as well as to receive information. He would sit down in myworkshop, and see me go through the various technical processes ofcasting, grinding, and polishing specula for reflecting telescopes.That was a pleasure to him, and a vast treat to me.

I had been busily occupied for some time in making careful investigationsinto the dark spots upon the Sun's surface. These spots are ofextraordinary dimensions, sometimes more than 10,000 miles in diameter.Our world might be dropped into them. I observed that the spots weresometimes bridged over by a streak of light, formed ofwillow-leaf-shaped objects. They were apparently possessed ofvoluntary motion, and moved from one side of the spot to the other.These flakes were evidently the immediate sources of the solar lightand heat. I wrote a paper on the subject, which I sent to the Literaryand Philosophical Society of Manchester.* [footnote...Memoirs of the Literary and Philosophical Society of Manchester,3d series, vol. i. p. 407. My first discovery of the "Willow-leaf"objects on the Sun's surface was made in June 1860.I afterwardsobtained several glimpses of them from time to time.But the occasionsare very rare when the bright sun can be seen in a tranquil atmospherefree from vibrations, and when the delicate objects on its surface canbe clearly defined. It was not until the 5th of June 1864 that Iobtained the finest sight of the Sun's spots and the Willow-leaf objects;it was then that I made a careful drawing of them, from which theannexed faithful engraving has been produced. Indeed I never had abetter sight of this extraordinary aspect of the Sun than on that day. ...]

The results of my observations were of so novel a character thatastronomers for some time hesitated to accept them as facts.Yet Sir John Herschel, the chief of astronomers, declared them to be"a most wonderful discovery"

[Image] Group of sun spots as seen by James Nasmyth, 5th June 1864.

I received a letter from Sir John, dated Collingwood, 2lst of May 1861,in which he said:

"I am very much obliged to you for your note, and by the sight of yourdrawings, which Mr. Maclaren was so kind as to bring over here theother day. I suppose there can be no doubt as to the reality of thewillow-leaved flakes, and in that case they certainly are the mostmarvellous phenomena that have yet turned up--had almost said in allNature--certainly in all Astronomy.

"What can they be? Are they huge phosphorised fishes? If so, whatmonsters! Or are they crystals? a kind of igneous snow-flakes?floating in a fluid of their own, or very nearly their own, specificgravity? Some kind of solidity or coherence they must have, or theywould not retain their shape in the violent movements of the atmospherewhich the change of the spots indicate.

"I observe that in the bridges all their axes have an approximateparallelism, and that in the penumbra they are dispersed, radiatingfrom the inside and the outside of the spot, giving rise to thatstriated appearance which is familiar to all observers of the spots.

"I am very glad that you have pitched your tent in this part of theworld, and I only wish it were a little nearer. You will anyhow havethe advantage at Penshurst of a much clearer atmosphere than in thenorth; but here, nearer the coast, I think we are still better off."Mr. Maclaren holds out the prospect of our meeting you at Pachley atno distant period, and I hope you will find your way ere long toCollingwood. I have no instruments or astronomical apparatus to showyou, but a remarkably pretty country, which is beginning to put on(rather late) its gala dress of spring?'

Sir John afterwards requested my permission to insert in hisOutlines of Astronomy, of which a new edition was about to appear, arepresentation of "the willow-leaved structure of the Sun's surface,"--which had been published in the Manchester transactions,--to whichI gladly gave my assent. Sir John thus expresses himself on thesubject: --"The curious appearance of the 'pores' of the Sun's surfacehas lately received a most singular and unexpected interpretation fromthe remarkable discovery of Mr. J. Nasmyth, who, from a series ofobservations made with a reflecting telescope of his own constructionunder very high magnifying powers, and under exceptional circumstancesof tranquillity and definition, has come to the conclusion that thesepores are the polygonal interstices between certain luminous objects ofan exceedingly definite shape and general uniformity of size,whose form (at least as seen in projection in the central portions ofthe disc) is that of the oblong leaves of a willow tree. These coverthe whole disc of the Sun (except in the space occupied by spots) incountless millions, and lie crossing each other in every imaginabledirection.... This most astonishing revelation has been confirmed to acertain considerable extent, and with some modifications as to the formof the objects, their exact uniformity of size and resemblance offigure, by Messrs. De la Rue, Pritchard and Stone in England,and M. Secchi in Rome."

On the 25th of February 1864, I received a communication fromMr. E. J. Stone, first assistant at the Royal Observatory, Greenwich.

The Astronomer-Royal, he said, "has placed in my hands your letter ofFebruary 20. Your discovery of the 'willow leaves' on the Solarphotosphere having been brought forward at one of the late meetings ofthe Royal Astronomical Society, my attention was attracted to thesubject. At my request, the Astronomer-Royal ordered of Mr. J. Simms areflecting eye-piece for our great equatorial. The eye-piece wascompleted about the end of January last, and at the first goodopportunity I turned the telescope on the Sun.

"I may state that my impression was, and it appears to have been theimpression of several of the assistants here, that the willow leavesstand out dark against the luminous photosphere. On looking at theSun, I was at once struck with the apparent resolvability of itsmottled appearance. The whole disc of the Sun, so far as I examinedit, appeared to be covered over with relatively bright rice-likeparticles, and the mottled appearance seemed to be produced by theinterlacing of these particles.

"I could not observe any particular arrangement of the particles, butthey appeared to be more numerous in some parts than in others.I have used the word 'rice-like' merely to convey a rough impression oftheir form. I have seen them on two occasions since, but not so wellas on the first day, when the definition was exceedingly good.

"on the first day that I saw them I called Mr Dunkin's attention tothem. He appears to have seen them. He says, however, that he shouldnot have noticed them if his attention had not been called to them."

The Astronomer Royal, in his report to the Admiralty on my discovery,said:

"an examination of the Sun's surface with the South-East Equatorial,under favourable circumstances, has convinced me of the accuracy of thedescription, which compares it with interlacing willow leaves or ricegrains."

In March 1864 I received a letter from my friend De la Rue, dated fromhis observatory at Cranford, Middlesex, in which he said: "I like goodhonest doubting. Before I had seen with my own eyes your willowleaves, I doubted their real existence, but I did not doubt your havingseen what you had drawn. But when I actually saw them for the firsttime, I could not restrain the exclamation, ' Why, here are Nasmyth'swillow leaves! ' It requires a very fine state of the atmosphere topermit of their being seen, as I have seen them on three or fouroccasions, when their substantial reality can no longer be doubted."* [footnote...Let me give another letter from my friend, dated the Observatory,Cranford, Middlesex, October 26, 1864. He said:-"I am quite pleased to learn that you like the large photograph.The first given to my friend was destined for and sent to you.No one has so great a claim on the fruit of my labours; for youinoculated me with the love of star-gazing, and gave me invaluable aidand advice in figuring specula. I daresay you may remember the firstoccasion on which I saw a reflecting telescope, which was then beingtried on the sun in a pattern loft at Patricroft. You may also recallthe volumes you wrote in answer to my troublesome questions.Yours very sincerely WARREN DE LA RUE." ...]

Sir John Herschel confirmed this information in a letter which Ireceived from him in the following May. He said "that Mr. De la Rueand a foreign gentleman, Hugo Muller, had been very successful inseeing and delineating the 'willow leaves' They are represented byMr. M. as packed together on the edge of a spot, and appear rather likea bunch of bristles or thorns. In other respects the individual formsagree very well with your delineations." Another observer haddiscovered a marvellous resemblance between the solar spots and thehollows left by the breaking and subsidence of bubbles, which rise whenoil varnish, which has moisture in it, is boiled, and the streakychannels are left by the retiring liquid. "I cannot help," addsSir John, "fancying a bare possibility of some upward outbreak,followed by a retreat of some gaseous matter, or some dilated portionof the general atmosphere struggling upwards, and at the same timeexpanding outwards. I can conceive of an up-surge of some highlycompressed matter, which relieved of pressure, will dilate laterallyand upwards to an enormous extent (as Poullett Scrope supposes of hislavas full of compressed gases and steam), producing the spots, and,in that case, the furrows might equally well arise in the originationas in the closing in of a spot."

I had the honour and happiness of receiving a visit from Sir JohnHerschel at my house at Hammerfield in the summer of 1864.He was accompanied by his daughter. They spent several days with us.The weather was most enjoyable. I had much conversation with Sir Johnas to the Sun spots and willow-leaf-shaped objects on the Sun'ssurface, as well as about my drawings of the Moon. I exhibited to himmy apparatus for obtaining sound castings of specula for reflectingtelescopes. I compounded the alloy, melted it, and cast a 10-inchspeculum on my peculiar common-sense system. I introduced the moltenalloy, chilled it in a metal mould, by which every chance of flaws andimperfections is obviated. I also showed him the action and results ofmy machine, by which I obtained the most exquisite polish and figurefor the speculum. Sir John was in the highest degree cognisant of theimportance of these details, as contributing to the final excellentresult. It was therefore with great pleasure that I could exhibitthese practical details before so competent a judge.

We had a great set-to one day in blowing iridescent soap bubbles from amixture of soap and glycerine. Some of the bubbles were of aboutfifteen inches diameter. By carefully covering them with a bell glass,we kept them for about thirty-six hours, while they went through theirchanges of brilliant colour, ending in deep blue. I contrived thismethod of preserving them by placing a dish of water below, within thecovering bell glass, by means of which the dampness of the airprevented evaporation of the bubble. This dodge of mine vastlydelighted Sir John, as it allowed him to watch the exquisite series ofiridescent tints at his tranquil leisure.

[Image] From a photograph of the Moon, exhibiting the bright radial lines.

[Image] Glass globe cracked by internal pressure, in illustration of the cause of the bright radial lines seen on the moon.

I had also the pleasure of showing him my experiment of cracking aglass globe filled with water and hermetically sealed. The water wasthen slightly expanded, on which the glass cracked. This was my methodof explaining the nature of the action which, at some previous periodof the cosmical history of the Moon, had produced those brightradiating lines that diverge from the lunar volcanic craters.Sir John expressed his delight at witnessing my practical illustrationof this hitherto unexplained subject, and he considered it quiteconclusive. I also produced my enlarged drawings of the Moon'ssurface, which I had made at the side of my telescope. These greatlypleased him and he earnestly urged me to publish them, accompanied witha descriptive account of the conclusions I had arrived at.I then determined to proceed with the preparations which I had alreadymade for my long contemplated work.

Among the many things that I showed Sir John while at Hammerfield, wasa piece of white calico on which I had got printed one million spots. [footnote...At a recent meeting of the Metropolitan Railway CompanyI exhibited one million of letters, in order to show the number ofpassengers (thirty-seven millions) that had been conveyed during theprevious twelve months. This number was so vast that my method onlyhelped the meeting to understand what had been done in the way ofconveyance. Mr. Macdonald of the Times, supplied me with one milliontype impressions, contained in sixty average columns of the Timesnewspaper. ...]

This was for the purpose of exhibiting one million in visible form.In astronomical subjects a million is a sort of unit, and it occurredto me to show what a million really is. Sir John was delighted andastonished at the sight. He went carefully over the outstretched piecewith his rule, measured its length and breath, and verified itscorrectness.

I also exhibited to him a diagram, which I had distributed amongst thegeologists at the meeting of the British Association at Ipswich in1851, showing a portion of the earth's curve, to the scale of one-tenthof an inch to a mile. I set out the height of Mont Blanc, Etna, andalso the depth of the deepest mine, as showing the almost incredibleminimum of knowledge we possess about even the merest surface of theglobe. This diagram was hailed by many as of much value, as conveyinga correct idea of the relative magnitude of geological phenomena incomparison with that of the earth itself:

On this subject Sir Thomas Mitchell, Surveyor-General of Australia,wrote to me at the time: "I will not obtrude upon you my crude notionsof my own, but merely say that you could not have sent the 'GeologicalStandard Scale' to one who better deserved it, if the claim in suchfavour is, as I suppose, to be estimated by the amount of the time ofone whole life, applied to the survey of great mountain ranges, andcoasts, rivers, etc. By this long practice of mine, you may know howappreciable this satisfactory standard scale is to your humble servant.

In the winter of 1865 I visited Italy. While at Rome, in April, I hadthe pleasure of meeting Otto W. von Struve, the celebrated Russianastronomer. He invited me to accompany him on a visit to Father Secchiat his fine observatory of the Collegio Romano. I accepted theinvitation with pleasure. We duly reached the Observatory when Struveintroduced me to the Father. Secchi gave me a most cordial andunlooked-for welcome. "This," he said, "is a most extraordinaryinterview; as I am at this moment making a representation of yourwillow-leaf-shaped constituents of the Solar surface!" He then pointedto a large black board, which he had daubed over with glue and wassprinkling over ( when we came in) with rice grains "That," said he,"is what I feel to be a most excellent representation of your discoveryas I see it, verified by the aid of my telescope." It appeared toFather Secchi so singular a circumstance that I should come upon him inthis sudden manner, while he was for the first time engaged inrepresenting what I had (on the spur of the moment when first seeingthem) described as willow-leaf-shaped objects. I thought that hisrepresentation of them, by scattering rice grains over his glue-coveredblack board, was apt and admirable; and so did Otto Struve.This chance meeting with these two admirable astronomers was one of thelittle bits of romance in my life.

I returned to England shortly after. Among our visitors at Hammerfieldwas Lord Lyndhurst. He was in his ninetieth year when he paid a visitto Tunbridge Wells. Charles Greville, Secretary to the Privy Council,wrote to me, saying that his Lordship complained much of the want ofsociety, and asked me to call upon him. I did so, and found himcheerful and happy.

I afterwards sent him a present of some of my drawings. He answered:"A thousand thanks for the charming etchings. I am especiallyinterested in Robinson Crusoe. He looks very comfortable, but I can'tsee his bed, which troubles me. The election ('Everybody for ever!')is wonderful. I should not like to be there. I hope we shall go toyou again one of these days, and have another peep into that wonderfultelescope."

To return to Sir John Herschel, We returned his visit at his house atCollingwood, near Hawkhurst. I found him in the garden, down upon hisknees, collecting crocus bulbs for next year's planting. Like myself,he loved gardening, and was never tired of it. I mention this as aninstance of his simple zeal in entering practically into all thatinterested him. At home he was the happy father and lover of hisfamily. One of his favourite pastimes, when surrounded by his childrenin the evening, was telling them stories. He was most happy andentertaining in this tranquil occupation. His masterly intellect couldgrasp the world and all its visible contents, and yet descend toentertain his children with extemporised tales. He possessedinformation of the most varied kind, which he communicated with perfectsimplicity and artlessness! His profound astronomical knowledge wascombined with a rich store of mechanical and manipulative faculty,which enabled him to take a keen interest in all the technical artswhich so materially aid in the progress of science. I shall neverforget the happy days that he spent with me in my workshop. His visitshave left in my mind the most cherished recollections. Our friendlyintercourse continued unbroken to the day of his death. The followingis the last letter I received from him:

COLLINGWOOD, March 10, 1871."MY DEAR SIR--A great many thanks for the opportunity of seeing yourmost exquisite photographs from models of lunar mountains. I hope youwill publish them. They will create quite an electric sensation.Would not one or two specimens of the apparently nonvolcanic mountainranges, bordering on the great plains, add to the interest? Excuse mywriting more, as I pen this lying on my back in bed, to which a fierceattack of bronchitis condemns me. With best regards to Mrs. Nasmyth,believe me yours very truly,

" J. F. W. HERSCHEL."

Scientific knowledge seems to travel slowly, It was not until the year1875, more than fourteen years after my discovery of the willow-leavedbridges over the Sun's spots that I understood they had been acceptedin America. I learned this from my dear friend William Lassell.His letter was as follows: --"I see the Americans are appreciatingyour solar observations. A communication I have lately received fromthe Alleghany Observatory remarks 'that he (Mr. Nasmyth) appears tohave been the first to distinctly call attention to the singularindividuality of the minute components of the photosphere; and thisseems in fairness to entitle him to the credit of an importantdiscovery, with which his name should remain associated.'"

I proceeded to do that which Sir John Herschel had so earnestlyrecommended, that is, to write out my observations on the Moon.It was a very serious matter, for I had never written a book before.It occupied me many years, though I had the kind assistance of myfriend James Carpenter, then of the Royal Observatory, Greenwich.The volcanoes and craters, and general landscape scenery of the Moon,had to be photographed and engraved, and this caused great labour.

At length the book, entitled The Moon, considered as a Planet, a World,and a Satellite, appeared in November 1874. It was received with muchfavour and passed into a second edition. A courteous and kind reviewof the book appeared in the Edinburgh; and the notices in otherperiodicals were equally favourable. I dedicated the volume to theDuke of Argyll, because I had been so long associated with him ingeological affairs, and also because of the deep friendship which Ientertained for his Grace. I presented the volume to him as well as tomany other of my astronomical friends. I might quote their answers atgreat length, from the Astronomer-Royal downwards. But I will quotetwo--one from a Royal Academician and another from a Cardinal.The first was from Philip H. Calderon. He said:

"Let me thank you many times for your kind letter, and for yourglorious book. It arrived at twelve to-day, and there has been nopainting since. Once having taken it up, attracted by theillustrations, I could not put it down again. I forgot everything;and, indeed, I have been up in the Moon. As soon as these few words ofthanks are given, I am going up into the Moon again. What a comfort itis to read a scientific work which is quite clear, and what a gift itis to write thus!

"The photographs took my breath away. I could not understand how youdid them, and your explanation of how you built the models from yourdrawings only changed the wonder into admiration. Only an artist couldhave said what you say about the education of the eye and of the hand.You may well understand how it went home to me. Ever gratefully yours,

PHILIP H. CALDERON."

I now proceed to the Cardinal. I was present at one of the receptionsof the President of the Royal Society at Burlington House, when I wasintroduced to Cardinal Manning as "The Steam Hammer!" After a cordialreception he suddenly said, "But are you not also the Man in the Moon?"Yes, your Eminence. I have written a book about the Moon, and I shallbe glad if you will accept a copy of it?" "By all means," he said,"and I thank you for the offer very much." I accordingly sent the copy,and received the following answer:

"MY DEAR MR.NASMYTH--When I asked you to send me your book on theMoon, I had no idea of its bulk and value, and I feel ashamed of myimportunity, yet more than half delighted at my sturdy begging.

"I thank you for it very sincerely. My life is one of endless work,leaving me few moments for reading. But such books as yours refresh melike a clover field.

I may also mention that I received a charming letter from Miss Herschel,the daughter of the late Astronomer.

"Is it possible," she said, "that this beautiful book is destined byyou as a gift to my most unworthy self? I do not know, indeed, how sufficiently to thank you, or even to express my delight in beingpossessed of so exquisite and valuable a work, made so valuable, too,by the most kind inscription on the first page! I fear I shall be veryvery far from understanding the theories developed in the book, thoughwe have been endeavouring to gather some faint notion of them from thereviews we have seen; but it will be of the greatest interest for us totry and follow them under your guidance, and with the help of theseperfectly enchanting photographs, which, I think, one could never betired of looking at.

"How well I remember the original photographs, and the oil paintingwhich you sent for dear papa's inspection, and which he did so enjoy!and also the experiment with the glass globe, in which he was sointerested, at your own house. We cannot but think how he would haveappreciated your researches, and what pleasure this lovely book wouldhave given him. Indeed, I shall treasure it especially as aremembrance of that visit, which is so completely connected in mythoughts with him, as well as with your cordial kindness, as a precioussouvenir, of which let me once more offer you my heartfelt thanks.I remain, my dear sir, yours very truly and gratefully,

"ISABELLA HERSCHEL."

I cannot refrain from adding the communication I received from my dearold friend William Lassell. "I do not know," he said,"how sufficiently to thank you for your most kind letter, and thesuperb present which almost immediately followed it. My pleasure wasgreatly enhanced by the consideration of how far this splendid workmust add to your fame and gratify the scientific world.The illustrations are magnificent, and I am persuaded that no book hasever been published before which gives so faithful, accurate,and comprehensive a picture of the surface of the Moon. The work musthave cost you much time, thought, and labour, and I doubt not you willnow receive a gratifying, if not an adequate reward."

After reading the book Mr. Lassell again wrote to me. "I am indebtedto your beautiful book, "he said, "for a deeper interest in the Moonthan I ever felt before.... I see many of your pictures have beentaken when the Moon was waning, which tells me of many a shiveringexposure you must have had in the early mornings,... I was sorry tofind from your letter that you had a severe cold, which made you veryunwell. I hope you have ere this perfectly recovered. I supposemaladies of this kind must be expected to take rather severe hold of usnow, as we are both past the meridian of life. I am, however,very thankful for the measure of health I enjoy, and the pleasuremechanical pursuits give me. I fully sympathise with you in thecontempt (shall I say?) which you feel for the taste of so many peoplewho find their chief pleasure in 'killing something,' and how oftentheir pleasures are fatal! Two distinguished men killed only the otherday in hunting. For my part I would rather take to the bicycle and domy seventeen miles within the hour."

He proceeds: "I have no doubt your windmill is very nicely contrived,and has afforded you much pleasure in constructing it.The only drawback to it is, that in this variable climate it is apt tostrike work, and in the midst of a job of polishing I fear no increaseof wages would induce it to complete its task! If water were plentiful,you might make it pump up a quantity when the wind served, to be usedas a motive power when you chose."

This reference alludes to a windmill which I erected on the top of myworkshop, to drive the apparatus below. It was the mirror of areflecting telescope which was in progress. The windmill went on nightand day, and polished the speculum while I slept. In the small hoursof the morning I keeked through the corner of the window blinds and sawit hard at work. I prefer, however, a small steam-engine, which worksmuch more regularly.

It is time to come to an end of my Recollections. I have endeavouredto give a brief resume of my life and labours. I hope they may proveinteresting as well as useful to others. Thanks to a good constitutionand a frame invigorated by work, I continue to lead, with my dear wife,a happy life. I still take a deep interest in mechanics, in astronomy,and in art. It is a pleasure to me to run up to London and enjoy thecollections at the National Gallery, South Kensington, and the RoyalAcademy. The Crystal Palace continues to attract a share of myattention, though, since the fire, it has been greatly altered.I miss, too, many of the dear accustomed faces of the old friends weused to meet there. Still we visit it, and leave to memory the fillingup of what is gone. All things change, and we with them.The following Dial of Life gives a brief summary of my career.It shows the brevity of life, and indicates the tale that is soon told.The first part of the semicircle includes the passage from infancy toboyhood and manhood. While that period lasts, time seems to pass veryslowly. We long to be men, and doing men's work. What I have calledThe Tableland of Life is then reached. Ordinary observation shows thatbetween thirty and fifty the full strength of body and mind is reached;and at that period we energise our faculties to the utmost.

[Image] The Dial of Life

Those who are blessed with good health and a sound constitution mayprolong the period of energy to sixty or even seventy; but Nature'slaws must be obeyed, and the period of decline begins, and goes on withaccelerated rapidity. Then comes Old Age; and as we descend thesemicircle towards eighty, we find that the remnant of life becomesvague and cloudy. By shading off, as I have done, the portion of thearea of the diagram according to the individual age, every one may seehow much of life is consumed, and what is left--D.V.. Here is mybrief record:

AGE YEAR.-- 1808. BORN 19TH AUGUST.9 1817. WENT TO THE HIGH SCHOOL, EDINBURGH.13 1821. ATTENDED THE SCHOOL OF ARTS.21 1829. WENT TO LONDON, TO MAUDSLAY'S.23 1831. RETURNED TO EDINBURGH, TO MAKE MY ENGINEERS' TOOLS.26 1834. WENT TO MANCHESTER, TO BEGIN BUSINESS.28 1836. REMOVED TO PATRICROFT, AND BUILT THE BRIDGEWATER FOUNDRY.31 1839. INVENTED THE STEAM HAMMER.32 1840. MARRIAGE.34 1842. FIRST VISIT TO FRANCE AND ITALY.35 1843. VISIT TO ST. PETERSBURG, STOCKHOLM, DANNEMORA.37 1845. APPLICATION OF THE STEAM HAMMER TO PILE-DRIVING.48 1856. RETIRED FROM BUSINESS, TO ENJOY THE REST OF MY LIFE IN THE ACTIVE PURSUIT OF MY MOST FAVOURITE OCCUPATIONS.

I have not in this list referred to my investigations in connectionwith astronomy. All this will be found referred to in the text.It only remains for me to say that I append a resume of my inventions,contrivances, and workshop "dodges," to give the reader a summary ideaof the Active Life of a working mechanic. And with this I end my tale.

1825. A mode of applying Steam Power for the Traction of Canal Barges, without injury to the Canal Banks.

A CANAL having been formed to connect Edinburgh with the Forth andClyde Canal, and so to give a direct waterway communication betweenEdinburgh and Glasgow, I heard much talk about the desirableness ofsubstituting Steam for Horse power as the means of moving the boats andbarges along the canal. But, as the action of paddle wheels had beenfound destructive to the canal banks, no scheme of that nature could beentertained. Although a tyro in such matters, I made an attempt tosolve the problem, and accordingly prepared drawings, with adescription of my design, for employing Steam power as the tractiveagency for trains of canal barges, in such a manner as to obviate allrisk of injury to the banks.

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The scheme consisted in laying a chain along the bottom of the canal,and of passing any part of its length between three grooved and notchedpulleys or rollers, made to revolve with suitable velocity by means ofa small steam-engine placed in a tug-boat, to the stern of which atrain of barges was attached.* [footnote...Had this simple means of "tugging" vessels through water-ways beenemployed in our late attempts to ascend the rapids of the Nile, somevery important results might have issued from its adoption. ...]The steam-engine could thus warp its way along the chain, taking it upbetween the rollers of the bow of the tug-boat, and dropping it intothe water at the stern, so as to leave the chain at the service of thenext following tug-boat with its attached train of barges. By thissimple mode of employing the power of a steam-engine for canal boattraction, all risk of injury to the banks would be avoided, as thechain and not the water of the canal was the fulcrum or resistancewhich the steam-engine on the tug-boat operated upon in thus warpingits way along the chain; and thus effectually, without slip or otherwaste of power, dragging along the train of barges attached to thestern of the steam-tug. I had arranged for two separate chains,so as to allow trains of barges to be conveyed along the canal inopposite directions, without interfering with each other.

I submitted a complete set of drawings, and a full description of mydesign in all its details, to the directors of the Canal Company;and I received a complimentary acknowledgment of them in writing. Butsuch was the prejudice that existed, in consequence of the injury tothe canal banks resulting from the use of paddle Wheels, that itextended to the use of steam power in any form, as a substitute forordinary horse traction; and although I had taken every care to pointout the essential difference of my system (as above indicated) by whichall such objections were obviated, my design was at length courteouslydeclined, and the old system of horse traction continued.

In 1845 I had the pleasure to see this simple mode of moving vesselsalong a definite course in most successful action at the ferry acrossthe Hamoaze at Devonport, in which my system of employing the power ofa steam-engine on board the ferry boat, to warp its way along asubmerged chain lying along the bottom of the channel from side to sideof the ferry, was most ably carried out by my late excellent friend,James Rendell, Esq., C.E., and is still, I believe, in daily action,giving every satisfaction.

1826. An Instrument for Measuring the Total and Comparative Expansion of all Solid Bodies.

My kind friend and patron, Professor Leslie, being engaged in someinvestigations in which it was essential to know the exact comparativetotal expansion in bulk of metals and other solid bodies, under thesame number of degrees of heat, mentioned the subject in the course ofconversation. The instrument at that time in use was defective inprinciple as well as in construction, and the results of itsapplication were untrustworthy. As the Professor had done me the honourto request me to assist him in his experiments, I had the happiness tosuggest an arrangement of apparatus which I thought might obviate thesources of error; and, with his approval, I proceeded to put it inoperation.

My contrivance consisted of an arrangement by means of which the metalbar or other solid substance, whose total expansion under a givennumber of degrees of heat had to be measured, was in a manner itselfconverted into a thermometer. Absolutely equal bulks of each solid wereplaced inside a metal tube or vessel, and surrounded with an exactequal quantity of water at one and the same normal temperature.A cap or cover, having a suitable length of thermometer tube attachedto it, was then screwed down, and the water of the index tube wasadjusted to the zero point of the scale attached to it, the whole beingat say 50deg of heat, as the normal temperature in each case. Theapparatus was then heated up to say 200deg by immersion in water atthat temperature. The expansion of the enclosed bar of metal or othersolid substance under experiment caused the water to rise above thezero, and it was accordingly so indicated on the scale attached to thecap tube. In this way we had a thermometer whose bulb was for the timebeing filled with the solid under investigation,--the water surroundingit imply acting as the means by which the expansion of each solid undertrial was rendered visible, and its amount capable of being ascertainedand recorded with the utmost exactness, as the expansion of the waterwas in every case the same, and also that of the instrument itselfwhich was "a constant quantity."

In this way we obtained the correct relative amount of expansion inbulk of all the solid substances experimented upon. That each bar ofmetal or other solid substance was of absolutely equal bulk, wasreadily ascertained by finding that each, when weighed in water,lost the exact same weight.

[Image] James Nasmyth's Expansometer, 1826.

My friend, Sir David Brewster, was so much pleased with the instrumentthat he published a drawing and description of it in the EdinburghPhilosophical Journal, of which he was then editor.

1827. A Method of increasing the Effectiveness of Steam by super-heating it on its Passage from the Boiler to the Engine.

One or the earliest mechanical contrivances which I made was forpreventing water, in a liquid form, from passing along with the steamfrom the boiler to the cylinder of the steam-engine.The first steam-engine I made was employed in grinding oil colours formy father's use in his paintings. When I set this engine to work forthe first time I was annoyed by slight jerks which now and thendisturbed the otherwise smooth and regular action of the machine.After careful examination I found that these jerks were caused by thesmall quantities of water that were occasionally carried along with thecurrent of the steam, and deposited in the cylinder, where itaccumulated above and below the piston, and thus produced the jerks.

In order to remove the cause of these irregularities, I placed aconsiderable portion of the length of the pipe which conveyed the steamfrom the boiler to the engine within the highly heated side flue of theboiler, so that any portion of water in the liquid form which mightchance to pass along with the steam, might, ere it reached thecylinder, traverse this highly-heated steam pipe, and, in doing so,be converted into perfectly dry steam, and in that condition enter thecylinder. On carrying this simple arrangement into practice, I foundthe result to be in every way satisfactory. The active littlesteam-engine thence-forward performed its work in the most smooth andregular manner.

So far as I am aware, this early effort of mine at mechanicalcontrivance was the first introduction of what has since been termed"super-heated steam"--a system now extensively employed, and yieldingimportant results, especially in the case of marine steam-engines.Without such means of supplying dry steam to the engines, the latterare specially liable to "break-downs," resulting from water,in the liquid form, passing into the cylinders along with the steam.

1828. A Method of "chucking" delicate Metal-work, in order that it may be turned with perfect truth

In fixing portions of work in the turning-lathe, one of the mostimportant points to attend to is, that while they are held withsufficient firmness in order to be turned to the required form, theyshould be free from any strain which might in any way distort them.In strong and ponderous objects this can be easily accomplished by duecare on the part of an intelligent workman. It is in operating by thelathe on delicate and flexible objects that the utmost care isrequisite in the process of chucking, as they are easily strained outof shape by fastening them by screws and bolts, or suchlike ordinarymeans. This is especially the case with disc-like objects. As I had onseveral occasions to operate in the lathe with this class of work Icontrived a method of chucking or holding them firm while receiving therequired turning process, which has in all cases proved most handy andsatisfactory.

This method consisted of tinning three, or, if need be, more parts ofthe work, and laying them down on a tinned face-plate or chuck,which had been heated so as just to cause the solder to flow. As soonas the solder is cooled and set, the chuck with its attached work maythen be put in the lathe, and the work proceeded with until it iscompleted. By again heating the chuck, by laying upon it a piece ofred-hot iron, the work, however delicate, can be simply lifted off,and will be found perfectly free from all distortion.

I have been the more particular in naming the use of three points ofattachment to the chuck or face-plate, as that number is naturally freefrom any risk of distortion. I have on so many occasions found thegreat value of this simple yet most secure mode of fixing delicate workin the lathe, that I feel sure that any one able to appreciate itspractical value will be highly pleased with the results of itsemployment.

The same means can, in many cases, be employed in fixing delicate workin the planing-machine. All that is requisite is to have a clean-planedwrought-iron or brass fixing-plate, to which the work in hand can beattached at a few suitable parts with soft solder, as in the case ofthe turning lathe above described.

1828. A Method of casting Specula for Reflecting Telescopes, so as to ensure perfect Freeness from Defects, at the same time enhancing the Brilliancy of the Alloy.

My father possessed a very excellent achromatic spy-glass of 2 inchesdiameter. The object-glass was made by the celebrated Ramsden.When I was about fifteen I used it to gaze at the moon, planets, andsun-spots. Although this instrument revealed to me the generalcharacteristic details of these grand objects, my father gave me awonderful account of what he had seen of the moon's surface by means ofa powerful reflecting telescope of 12 inches diameter, made by Short--that justly celebrated pioneer of telescope making. It had been erectedin a temporary observatory on the Calton Hill, Edinburgh. Thesedescriptions of my father's so fired me with the desire to obtain asight of the glorious objects in the heavens through a more powerfulinstrument than the spy-glass, that I determined to try and make areflecting telescope which I hoped might in some degree satisfy myardent desires.

I accordingly searched for the requisite practical instruction in thepages of the Encyclopedia Britannica, and in other books that professedto give the necessary technical information on the subject. I found,however, that the information given in books--at least in the booksto which I had access was meagre and unsatisfactory. Nevertheless I setto work with all earnestness, and began by compounding the requisitealloy for casting a speculum of 8 inches diameter. This alloy consistedof 32 parts of copper, 15 parts of grain tin, and 1 part of white arsenic.These ingredients, when melted together, yielded a compound metal whichpossessed a high degree of brilliancy. Having made a wooden pattern formy intended 8-inch diameter speculum, and moulded it in sand,I cast this my first reflecting telescope speculum according to thebest book instructions. I allowed my casting to cool in the mould inthe slowest possible manner; for such is the excessive brittleness ofthis alloy (though composed of two of the toughest of metals) that inany sudden change of temperature, or want of due delicacy in handlingit, it is very apt to give way, and a fracture more or less serious issure to result. Even glass, brittle though it be, is strong incomparison with speculum metal of the above proportions, though,as I have said, it yields the most brilliant composition.

Notwithstanding the observance of all due care in respect of theannealing of the casting by slow cooling, and the utmost care anddelicate handling of it in the process of grinding the surface into therequisite curve and smoothness suitable to receive the final polish,--I was on more than one occasion inexpressibly mortified by the suddendisruption and breaking up of my speculum. Thus many hours of anxiouscare and labour proved of no avail. I had to begin again and proceedda capo. I observed, however, that the surplus alloy that was left inthe crucible, after I had cast my speculum, when again melted andpoured out into a metal ingot mould, yielded a cake that, brittlethough it might be, was yet strong in comparison with that of thespeculum cast in the sand mould; and that it was also, judging from thefragments chipped from it, possessed of even a higher degree ofbrilliancy.

The happy thought occurred to me of substituting an open metal mouldfor the closed sand one. I soon had the metal mould ready for casting.It consisted of a base plate of cast iron, on the surface of which Iplaced a ring or hoop of iron turned to fully the diameter of theintended speculum, so as to anticipate the contraction of the alloy.The result of the very first trial of this simple metal mould was mostsatisfactory. It yielded me a very perfect casting: and it passedsuccessively through the ordeal of the first rough grinding, andeventually through the processes of polishing, until in the end itexhibited a brilliancy that far exceeded that of the sand mouldcastings.

The only remaining difficulty that I had to surmount was the risk ofdefects in the surface of the speculum. These sometimes result from thefirst splash of the melted metal as it is poured into the ring mould.The globules sometimes got oxidised before they became incorporatedwith the main body of the inflowing molten alloy: and dingy spots inthe otherwise brilliant alloy were thus produced. I soon mastered this,the only remaining source of defect, by a very simple arrangement.In place of pouring the melted alloy direct into the ring mould, Iattached to the side of it what I termed a "pouring pocket;"which communicated with an opening at the lower edge of the ring,and by a self-acting arrangement by which the mould plate was slightlytilted up, the influx of the molten alloy advanced in one unbrokentide. As soon as the entire surface of the mould plate was covered bythe alloy, its weight overcame that of my up-tilting counterpoise,and allowed the entire apparatus to resume its exact level. Theresulting speculum was, by these simple arrangements, absolutelyperfect in soundness. It was a perfect casting, in all respects worthyof the care and labour which I invested in its future grinding andpolishing, and enabled it to perform its glorious duties as the grandessential part of a noble reflecting telescope!

[Image]

A. Chill plate of cast iron turned to the curve of the speculum B.Turned hoop of wrought iron with opening at O. C. Pouring pocket. D.Counterpoise, By which the chill plate is tilted up The largest figurein the engraving is the annealing tub of cast iron filled with sawdust,where the speculum is placed to cool as slowly as possible.

The rationale of the strength of specula cast in this metal mouldsystem, as compared with the treacherous brittleness of those cast insand moulds, arises simply from the consolidation of the molten metalpool taking place first at the lower surface, next the metal base ofthe mould--the yet fluid alloy above satisfying the contractilerequirements of that immediately beneath it; and so on in succession,until the last to consolidate is the top or upper stratum.Thus all risk of contractile tension, which is so dangerously eminentand inherent in the case of sand-mould castings, made of so exceedinglybrittle an alloy as that of speculum metal, is entirely avoided.By the employment of these simple and effective improvements in the artof casting the specula for reflecting telescopes, and also by thecontrivance and employment of mechanical means for grinding andpolishing them, I at length completed my first 8-inch diameterspeculum, and mounted it according to the Newtonian plan. I was mostamply rewarded for all the anxious labour I had gone through inpreparing it, by the glorious views it yielded me of the wonderfulobjects in the heavens at night. My enjoyment was in no small degreeenhanced by the pleasure it gave to my father, and to many intimatefriends. Amongst these was Sir David Brewster, who took a most livelyand special interest in all my labours on this subject.

In later years I resumed my telescope making enjoyments, as adelightful and congenial relaxation from the ordinary run of mybusiness occupations. I constructed several reflecting telescopes,of sizes from 10-inch to 20-inch diameter specula. I had also thepleasure of assisting other astronomical friends, by casting andgrinding specula for them. Among these I may mention my late dearfriend William Lassell, and my excellent friend Warren de la Rue,both of whom have indelibly recorded their names in the annals ofastronomical science. I know of no subject connected with the pursuitof science which so abounds with exciting and delightful interest asthat of constructing reflecting telescopes. It brings into play everyprinciple of constructive art, with the inexpressibly glorious rewardof a more intimate acquaintance with the sublime wonders of theheavens, I communicated in full detail all my improvements in the artof casting, grinding, and polishing the specula of reflectingtelescopes, to the Literary and Philosophical Society of Manchester,illustrating my paper with many drawings. But as my paper was ofconsiderable length, and as the illustrations would prove costly toengrave, it was not published in the Society's Transactions. They arestill, however, kept in the library for reference by those who take aspecial interest in the subject.

1829. A Mode of transmitting Rotary Motion by means of a Flexible Shaft, formed of a Coiled Spiral Wire or Rod of Steel.

While assisting Mr. Maudslay in the execution of a special piece ofmachinery, in which it became necessary to have some holes drilled inrather inaccessible portions of the work in hand, and where theemployment of the ordinary drill was impossible, it occurred to me thata flexible shaft, formed of a closely coiled spiral of steel wire,might enable us to transmit the requisite rotary motion to a drillattached to the end of this spiral shaft. Mr. Maudslay was much pleasedwith the notion, and I speedily put it in action by a close coiledspiral wire of about two feet in length.

This was found to transmit the requisite rotary motion to the drill atthe end of the spiral with perfect and faithful efficiency.The difficulty was got over, to Mr. Maudslay's great satisfaction.

So far as I am aware, such a mode of transmitting rotary motion was newand original. The device was useful, and proved of essential service inother important applications. By a suitably close coiled spiral steelwire I have conveyed rotary motion quite round an obstacle, such as isindicated in the annexed figure.

[Image]

It has acted with perfect faithfulness from the winch handle at A tothe drill at B. Any ingenious mechanic will be able to appreciate thevalue of such a flexible shaft in many applications. Four years ago Isaw the same arrangement in action at a dentist's operating-room, whena drill was worked in the mouth of a patient to enable a decayed toothto be stopped. It was said to be the last thing out in "Yankee notions."It was merely a replica of my flexible drill of 1829.

1829. A Mode of cutting Square or Hexgonal Collares Nuts or Bolt-Heads by means of a Revolving File or Cutter.

This method is refrered to, and drawings given, in the text,pp. 141, 142.

1829. A Investigation into the Origin and Mode of writing the Cuneiform Character

This will be found described in the next and final chapter

1836. A Machine for cutting the Key-Grooves in Metal Wheels and Belt Pulleys, of ANY Diameter.

The fastening of wheels and belt pulleys to shafts, so as to enablethem to transmit rotary motion, is one of the most frequently-recurringprocesses in the construction of machinery. This is best effected bydriving a slightly tapered iron or steel wedge, or "key" as it istechnically termed, into a corresponding recess, or flat part of theshaft, so that the wheel and shaft thus become in effect one solidstructure.

The old mode of cutting such key-grooves in the eyes of wheels wasaccomplished by the laborious and costly process of chipping andfiling. Maudslay's mortising machine, which he contrived for the Blockmachinery, although intended originally to operate upon wood, containedall the essential principles and details required for acting on metals.Mr. Richard Roberts, by some excellent modifications, enabled it tomortise or cut out the key-grooves in metal wheels, and this methodsoon came into general use. This machine consisted of a vertical slidebar, to the lower end of which was attached the steel mortising tool,which received its requisite up and down motion from an adjustablecrank, through a suitable arrangement of the gearing. The wheel to beoperated upon was fixed to a slide-table, and gradually advanced,so as to cause the mortising tool to take successive cuts through thedepth of the eye of the wheel, until the mortise or key-groove hadattained its required depth.

The only drawback to this admirable machine was that its service waslimited in respect to admitting wheels whose half diameter did notexceed the distance from the back of the jaw of the machine to the faceof the mortise tool; so that to give to this machine the requisiterigidity and strength to resist the strain on the jaw, due to themortising of the key-grooves, in wheels of say 6 feet diameter,a more massive and cumbrous frame work was required, which was mostcostly in space as well as in money.

In order to obviate this inconvenience, I designed an arrangement of akey-groove mortising machine. It was capable of operating upon wheelsof any diameter, having no limit to it capacity in that respect.It was, at the same time, possessed in respect of the principle onwhich it was arranged, of the power of taking a much deeper cut,there being an entire absence of any source of springing or elasticityin its structure. This not only enabled the machine to perform its workwith more rapidity, but also with more precision. Besides, it occupiedmuch less space in the workshop, and did not cost above one-third ofthe machines formerly in use. It gave the highest satisfaction to thosewho availed themselves of its effective Services.

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A comparison of Fig. 1--which represents the general arrangement ofthe machine in use previous to the introduction of mine--with that ofFig. 2, may serve to convey some idea of their relative sizes. Fig. 1shows a limit to the admission of wheels exceeding 6 feet diameter,Fig. 2 shows an unlimited capability in that respect.

1836. An Instrument for finding and marking the Centres of Cylindrical Rods or Bolts about to be turned on the Lathe.

One of the most numerous details in the structure of all classes ofmachines is the bolts which serve to hold the various parts together.As it is most important that each bolt fits perfectly the hole itbelongs to, it is requisite that each bolt should, by the process ofturning, be made perfectly cylindrical. In preparing such bolts,as they come from the forge, in order to undergo the process ofturning, they have to be "centred;" that is, each end has to receive ahollow conical indent, which must agree with the axis of the bolt.To find this in the usual mode, by trial and frequent error, is a mosttedious process, and consumes much valuable time of the workman as wellas his lathe.

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In order to obviate the necessity for this costly process, I devisedthe simple instrument, a drawing of which is annexed. The use of thisenabled any boy to find and mark with absolute exactness and rapiditythe centres of each end of bolts, or suchlike objects. All that wasrequired was to place the body of the bolt in the V-shaped supports,and to gently cause it to revolve, pressing it longitudinally againstthe steel-pointed marker, which scratched a neat small circle in thetrue centre or axis of the bolt. This small circle had its centreeasily marked by the indent of a punch, and the work was thus ready forthe lathe. This humble but really important process was accomplishedwith ease, rapidity, and great economy.

1836. Improvement in Steam-Engine Pistons, and in Water and Air-Pump Buckets, so as to lessen Friction and dispense with Packing.

The desire to make the pistons of steam-engines and air-pump buckets ofcondensing engines perfectly steam and water tight has led to thecontrivance of many complex and costly constructions for the purpose ofpacking them. When we take a commonsense view of the subject, we findthat in most cases the loss of power resulting from the extra frictionneutralises the expected saving. This is especially the case with theair-pump bucket of a condensing steam-engine, as it is in reality muchmore a water than an air pump. But when it is constructed with a deepwell-fitted bucket, entirely without packing, the loss sustained bysuch an insignificant amount of leakage as may occur from the want ofpacking is more than compensated by the saving of power resulting fromthe total absence of friction.

The first condensing steam-engine to which I applied an air-pumpbucket, entirely without packing, was the forty horsepower engine,which I constructed for the Bridgewater Foundry. It answered itspurpose so well that, after twenty years' constant working,the air-pump cover was taken off, out of curiosity, to examine thebucket, when it was found in perfect order. This system, in which Idispensed with the packing for air-pump buckets of condensingsteam-engines, I have also applied to the pistons of the steamcylinders, especially those of high-pressure engines of the smallervertical construction, the stroke of which is generally short andrapid. Provided the cylinder is bored true, and the piston is carefullyfitted, and of a considerable depth in proportion to its diameter,such pistons will be found to perform perfectly all their functions,and with a total absence of friction as a direct result of the absenceof packing. By the aid of our improved machine tools, cylinders can nowbe bored with such perfect accuracy, and the pistons be fitted to themwith such absolute exactness, that the small quantity of water whichthe steam always deposits on the upper side of the piston, not onlyserves as a frictionless packing, but also serves as a lubricant of themost appropriate kind. I have applied the same kind of piston toordinary water-pumps, with similar excellent results. In most cases ofright packed pistons we spend a shilling--to save sixpence--a not unfrequent result of "so-called" refined improvements.

1836. An instantaneous Mode of producing graceful Curves, suitable for designing Vases and other graceful objects in Pottery and Glass.

The mode referred to consists in giving a rapid "switch" motion to apencil upon a piece of paper, or a cardboard, or a smooth metal plate;and then cutting out the curve so produced, and employing it as apattern or "template," to enable copies to be traced from it.When placed at equal distances, and at equal angles on each side of acentral line, so as to secure perfect symmetry of form according to thenature of the required design, the beauty of these "instantaneous"curves, as I term them, arises from the entire absence of any suddenvariation in their course. This is due to the momentum of the hand when"switching" the pencil at a high velocity over the paper.By such simple means was the beautiful curve produced, which is givenon the following page. It was produced "in a twinkling," if I may usethe term to express the rapidity with which it was "switched."The chief source of the gracefulness of these curves consists in thealmost imperceptible manner in which they pass in their course from onedegree of curvature into another. I have had the pleasure of showingthis simple mode of producing graceful curves to several potters,who have turned the idea to good account. The illustrative figures onthe next page have all been drawn from "templates" whose curves were"switched" in the manner of Fig. A.

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1836. A Machine for planing the smaller or detail parts of Machinery, whether Flat or Cylindrical.

Although the introduction of the planing machine into the workshops ofmechanical engineers yielded results of the highest importance inperfecting and economising the production of machinery generally, yet,as the employment of these valuable machine tools was chiefly intendedto assist in the execution of the larger parts of machine manufacture,a very considerable proportion of the detail parts still continued tobe executed by hand labour, in which the chisel and the file were thechief instruments employed. The results were consequently veryunsatisfactory, both as regards inaccuracy and costliness.

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With the desire of rendering the valuable services of the PlaningMachine applicable to the smallest detail parts of machine manufacture,I designed a simple and compact modification of it, such as shouldenable any attentive lad to execute all the detail parts of themachines in so unerring and perfect a manner as not only to rival thehand work of the most skilful mechanic, but also at such a reduced costas to place the most active hand workman far into the background.The contrivance I refer to is usually known as "Nasmyth's Steam Arm."None but those who have had ample opportunities of watching the processof executing the detail parts of machines, can form a correct idea ofthe great amount of time that is practically wasted and unproductive,even when highly-skilled and careful workmen are employed. They have sofrequently to stop working, in order to examine the work in hand,to use the straight edge, the square, or the calipers, to ascertainwhether they are "working correctly." During that interval, the work ismaking no progress: and the loss of time on this account is not lessthan one-sixth of the working hours, and sometimes much more;though all this lost time is fully paid for in wages.

[Image] Apparatus for enabling the machine to execute segmented work

But by the employment of such a machine as I describe, even when placedunder the superintendence of well-selected intelligent lads, in whomthe faculty of good sight and nicety of handling is naturally in a highstate of perfection, any deficiency in their physical strength is amplycompensated by these self-acting machines. The factory engine suppliesthe labour or the element of Force, while the machines perform theirwork with practical perfection. The details of machinery are thusturned out with geometrical accuracy, and are in the highest sensefitted to perform their intended purposes.

1837. Solar Ray Origin of the form of the Egyptian Pyramids, Obelisks, etc.

This will be found described summarily in the next and final chapter.

1837. Method of reversing the action of Slide Lathes.

In the employment of Slide Turning Lathes, it is of great advantage tobe able to reverse the motion of the Slide so as to enable the turningtool to cut towards the Head of the Lathe or away from it, and also tobe able to arrest the motion of the Slide altogether, while all theother functions of the lathe are continued in action. All these objectsare attained by the simple contrivance represented in the annexedillustration.

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It consists of a lever E, moving on a stud-pin S, attached to the backof the head stock of the lathe T. This lever carries two wheels ofequal diameter marked B and G. These wheels can pitch into acorresponding wheel A, fixed on the back end of the lay spindle.When the handle of the lever E is depressed (as seen in the drawing)the wheel B is in gear with wheel A. while C is in gear with theslidescrew wheel D, and so moves the slide (say from the Head Stock ofthe lathe). On the other hand, when the lever E is elevated in positionE", wheel B is taken out of gear with A, while G is put in gear with A,and B is put in gear with D; and thus the Slide is caused to movetowards the Head Stock of the lathe. Again, where it is desired toarrest the motion of the Slide altogether, or for a time, as occasionmay require, the lever handle is put into the intermediate position E',which entirely severs the communication between A and D, and so arreststhe motion of the slide. This simple contrivance effectually served allits purposes, and was adopted by many machine tool-makers andengineers.

1838. Self-adjusting Bearings for the Shafts of Machinery

A frequent cause of undue friction and heating of rapidly rotatingmachinery arises from some inaccuracy or want of due parallelismbetween the rotating shaft or spindle and its bearing. This isoccasioned in most cases by some accidental change in the level of thesupports of the bearings. Many of the bearings are situated in darkplaces, and cannot be seen. There are others that are difficult ofaccess--as in the case of bearings of screw-propeller shafts.Serious mischief may result before the heating of the bearing proclaimsits dangerous condition. In some cases the timber work is set on fire,which may result in serious consequences.

In order to remove the cause of such serious mischief, I designed anarrangement of bearing, which enabled it, and the shaft working in it,to mutually accommodate themselves to each other under allcircumstances, and thus to avoid the danger of a want of due and mutualparallelism in their respective axes. This arrangement consisted ingiving to the exterior of the bearing a spherical form, so as, withinmoderate limits, to allow it to accommodate itself to any such changesin regard to mutual parallelism, as above referred to. In other cases,I employed what I may call Rocking centres, on which the Pedestal or"Plumber Block" rested; and thus supplied a self-adjusting means forobviating the evils resulting from any accidental change in the properrelative position of the shaft and its bearing. In all cases in which Iintroduced this arrangement, the results were most satisfactory.

In the case of the bearings of Blowing Fans, in which the rate ofrotation is naturally excessive, a spherical resting-place for thebearings enabled them to keep perfectly cool at the highest speed.This was also the case in the driving apparatus for machine tools,which is generally fixed at a considerable height above the machine.These spherical or self-adjusting bearings were found of great service.The apparatus, being generally out of convenient reach, is apt to getout of order unless duly attended to. But, whether or not, the savingof friction is in itself a reason for the adoption of such bearings.This may appear a trifling technical matter of detail; but its greatpractical value must be my excuse for mentioning it.

1838. Invention of Safety Foundry Ladle.

The safety ladle is described in the text, p. 202.

1838. Invention of the Steam Ram

My invention was made at this early date, long before the attack by thesteam-ram Merrimac upon the Cumberland, and other ships, in Hampton Roads,United States. I brought my plans and drawings under the notice of theAdmiralty in 1845; but nothing was done for many years. Much had beenaccomplished in rendering our ships shot-proof by the application ofiron plates; but it appeared to me that not one of them could existabove water after receiving on its side a single blow from aniron-plated steam-ram of 2000 tons. I said, in a letter to the Times,"As the grand object of naval warfare is the destruction by the mostspeedy mode of the ships of the enemy, why should we continue toattempt to attain this object by making small holes in the hull of theenemy when, by one single masterly crashing blow from a steam ram,we can crush in the side of any armour-plated ship, and let the waterrush in through a hole, 'not perhaps as wide as a church door or asdeep as a well, but 'twill serve'; and be certain to send her belowwater in a few minutes.* [footnote...In these days of armour-clad warships, when plates of enormousthickness are relied on as invulnerable, our Naval Constructors appearto forget that the actual structural strength of such ships depends onthe backing of the plates, which, be it ever so thick, would yield tothe cramming blow of a moderate-sized Ram. ...]

I published my description of the steam ram and its apparatus in theTimes of January 1853, and again addressed the Editor on the subjectin April 1862. General Sir John Burgoyne took up the subject,and addressed me in the note at the foot of this page.* [footnote...The following is the letter of General Sir John Burgoyne:

WAR OFFICE, PALL MALL, LONDON, 8th April 1862.

"General Sir John Burgoyne presents his compliments to Mr. Nasmyth,and was much pleased to find, by Mr. Nasmyth's letter in the Times ofthis day, certain impressions that he has held for some time confirmedby so good an authority. "A difficulty seems to be anticipated by manythat a steamer used as a ram with high velocity, if impelled upon aheavy ship, would, by the revulsion of the sudden shock, be liable tohave much of her gear thrown entirely out of order, parts displaced,and perhaps the boilers burst. Some judgment, however, may be formed onthis point by a knowledge of whether such circumstances have occurredon ships suddenly grounding; and even so, it may be a question whetherso great a velocity is necessary. "An accident occurred some twentyyears ago, within Sir John Burgoyne's immediate cognisance, that hasled him particularly to consider the great power of a ship acting as aram. A somewhat heavy steamer went, by accident or mismanagement, endon to a very substantial wharf wall in Kingstown Harbour, Dublin Bay.Though the force of the blow was greatly checked through the measurestaken for that purpose, and indeed so much so that the vessel itselfsuffered no very material injury, yet several of the massive granitestones of the facing were driven some inches in, showing the enormousforce used upon them. "Superior speed will be very essential to thesuccessful action of the ram; but by the above circumstance we mayassume that even a moderate speed would enable great effects to beproduced, at least on any comparatively weak point of even ironcladships, such as the rudder." ...]

In June 1870, I received a letter from Sir E. J. Reed, containing thefollowing extracts: --"I was aware previously that plans had beenproposed for constructing unarmoured steam rams, but I was notacquainted with the fact that you had put forward so well-maturerd ascheme at so early a date; and it has given me much pleasure to findthat such is the case. It has been a cause both of pleasure andsurprise to me to find that so long ago you incorporated into a designalmost all the features which we now regard as essential to rammingefficiency--twin screws and moderate dimensions for handiness,numerous water-tight divisions for safety, and special strengtheningsat the bow. Facts such as these deserve to be put on record....Meanwhile accept my congratulations on the great skill and foresightwhich your ram-design displays."

Collisions at sea unhappily afford ample evidence of the fatalefficiency of the ramming principle. Even ironclad ships have not beenable to withstand the destructive effect. The Vanguard and the Kurfurst now lie at the bottom of the sea in consequence of an accidental"end-on" ram from a heavy ship going at a moderate velocity. High speedin a Steam Ram is only desirable when the attempt is made to overtakean enemy's ship; but not necessary for doing its destructive work.A crash on the thick plates of the strongest Ironclad, from a Ram of2000 tons at the speed of four miles an hour, would drive them inwardswith the most fatal results.

1839. Invention of the Steam Hammer, in its general principles and details.

Described in text, p. 231.

1839. Invention of the Floating Mortar or Torpedo Ram.

For particulars and details, see Report of Torpedo Committee.

1839. A Double-faced Wedge-shaped Sluice-Valve for Main Street Water-pipes.

The late Mr. Wicksteed, engineer of the East London Water Company,having stated to me the inconvenience which had been experienced fromthe defects in respect of water-tightness, as well as the difficulty ofopening and closing the valves of the main water-pipes in the streets,I turned my attention to the subject. The result was my contrivance ofa double-faced wedge-shaped sluice-valve, which combined the desirableproperty of perfect water-tightness with ease of opening and closingthe valve.

This was effected by a screw which raised the valve from its bearingsat the first partial turn of the screw, after which there was nofurther resistance or friction, except the trifling friction of thescrew in its nut on the upper part of the sluice-valve. When screweddown again, it closed simultaneously the end of the entrance pipe andthat of the exit pipe attached to the valve case in the most effectivemanner.

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Mr. Wicksteed was so much pleased with the simplicity and efficiency ofthis valve that he had it applied to all the main pipes of his Company.When its advantages became known, I received many orders from otherwater companies, and the valves have since come into general use.The prefixed figure will convey a clear idea of the construction.The wedge form of the double-faced valve is conspicuous as thecharacteristic feature of the arrangement.* [footnote...At a meeting of the Institution of Civil Engineers, May 23, 1883,when various papers were read on Waterworks, Mr. H. I. Marten observedin the course of the discussion: --"It has been stated in Mr. Gamble'spaper (on the waterworks of Port Elizabeth) that the sluice valves areof the usual pattern. The usual patterns of the present day are inwonderful advance of those of thirty or forty years since. The greatimprovement originated with the introduction of 'the double-facedsluice-cock.' This sluice-cock, which had now superseded every otherdescription, was the creation of Mr. James Nasmyth's inventive genius.Mr. Marten said he well remembered the first reception of this usefulinvention, as he happened at that time to be a pupil of Mr. ThomasWicksteed. He was present when Mr. Wicksteed explained to Mr. Nasmyththe want he had experienced of a sluice-cock for Waterworks purposes,which should shut and remain perfectly tight against a pressure comingfrom either side. Mr. Marten had a lively recollection of theinstantaneous rapidity with which Mr. Nasmyth not only grasped butprovided for the requirement; so that almost by the time Mr. Wicksteedhad completed the statement of his want, Mr. Nasmyth had drawn upon theback of an old letter a rough sketch of the first double-facedsluice-cock; and in less than an hour had converted this rough sketchinto a full-sized working drawing; in the preparation of which it fellto Mr. Marten's lot to have the honour to assist. In his'Autobiography' Mr. Nasmyth referred to the conversation withMr. Wicksteed, and introduced a print of the drawing made upon theoccasion. The invention has been of the greatest use to the WaterworksEngineer, especially in connection with the constant supply system, inwhich it frequently happened that the pressure was sometimes againstone face of the sluice-cock, and sometimes against the other."--See Proceedings and Discussions of the Institution of Civil Engineers,1883, pp. 88, 89. ...]

Being under the impression that there are many processes in themanufacturing arts, in which a perfectly controllable compressing powerof vast potency might be serviceable, I many years ago prepared adesign of an apparatus of a very simple and easily executed kind,which would supply such a desideratum. It was possessed of a range ofcompressing or squeezing power, which far surpassed anything of thekind that had been invented. As above said, it was perfectlycontrollable; so as either to yield the most gentle pressure, or topossess the power of compressing to upwards of twenty thousand tons;the only limit to its power being in the materials employed in itsconstruction.

The principle of this enormously powerful compressing machine issimilar to that of the Hydraulic Press; the difference consistingprincipally in the substitution of what I term a Hydraulic Mattress inplace of the cylinder and ram of the ordinary hydraulic press.The Hydraulic Mattress consists of a square or circular water-tightvessel or flat bag formed of 1/2-inch thick iron or steel platessecurely riveted together; its dimensions being, say 15 feet square by3 feet deep, and having semicircular sides, which form enables theupper flat part of the Mattress to rise say to the extent of 6 inches,without any injury to the riveted joints, as such a rise or alterationof the normal form of the semicircular sides would be perfectlyharmless, and not exceed their capability of returning to their normalcurve when the 6-inch rise was no longer necessary, and the elevatingpressure removed.

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The action of this gigantic press is as follows. The Mattress A Ahaving been filled with water, an additional quantity is supplied by aforce pump, capable of forcing in water with a pressure of one ton tothe square inch; thus acting on an available surface of at least 144square feet surface--namely, that of the upper flat surface of theMattress. It will be forced up by no less a pressure than twentythousand tons, and transfer that enormous pressure to any article thatis placed between the rising table of the press and the upper table.When any object less thick than the normal space is required to receivethe pressure, the spare space must be filled with a suitable set ofiron flat blocks, so as to subject the article to be pressed to therequisite power.

As before stated, there may be many processes in the manufacturing artsin which such an enormous pressure may be useful; and this can beaccomplished with perfect ease and certainty. I trust that this accountof the principles and construction of such a machine may suggest someemployment worthy of its powers. In the general use of the Mattresspress, it would be best to supply the pressure water from anaccumulator, which should be kept constantly full by the action ofsuitable pumps worked by a small steam-engine. The great press wouldrequire the high-pressure water only now and then; so that it would notbe necessary to wait for the small pump to supply the pressure waterwhen the Mattress was required to be in action.

1840. A Tapping Square, or instrument by which Perfect Verticality of the Tapping of Screwed Holes is insured.

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The letter X shows how Screws are frequently made when tapped in theold mode; the letter T as they are always made when the Tapping Squareis employed.

1840. A Mode of turning Segmental Work in the Ordinary Lathe

In executing an order for twenty locomotive engines for the GreatWestern Railway Company, there was necessarily a repetition of detailparts. Many of them required the labour of the most skilful workmen,as the parts referred to did not admit of their being executed by thelathe or planing-machine in their ordinary mode of application.But the cost of their execution by hand labour was so great, and therisk of inaccuracy was so common (where extreme accuracy was essential),that I had recourse to the aid of special mechanical contrivances andmachine tools for the purpose of getting over the difficulty.The annexed illustration has reference to only one class of objects inwhich I effected great saving in the production, as well as greataccuracy in the work. It refers to a contrivance for producing by theturning-lathe the eighty bands of the eccentrics for these twentyengines. Being of a segmental form, but with a projection at eachextremity, which rendered their production and finish impossible by theordinary lathe, I bethought me of applying what is termed the manglemotion to the rim of a face plate of the lay, with so many pins in itas to give the required course of segmental motion for the turning toolto operate upon, between the projections C C in the illustration.

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I availed myself of the limited to-and-fro horizontal motion of theshaft of the mangle motion wheel, as it, at each end of the row of pegs--in the face plate (when it passes from the exterior to the interiorrange of them) in giving the feed motion to the tool in; the sliderest, "turned" the segmental exterior of the eccentric hoops.This it did perfectly, as the change of position of the small shaftoccurred at the exact time when the cut was at its termination,--thatbeing the correct moment to give the tool "the feed, or advance for thetaking of the next cut. The saving, in respect to time, was 10 to 1 incomparison with the same amount of work done by hand labour; while the"truth" or correctness of the work done by this handy littleapplication of the turning-lathe was absolutely perfect I have been themore particular in my allusion to this contrivance, as it is applicableto any lathe, and can perform work which no lathe without it canaccomplish. The unceasing industry of such machines is no smalladdition to their attractions, in respect to the production ofunquestionably accurate work.

1843. Invention of the Steam Hammer Pile-driver.

Described in text, p. 261.

1843. A Universal Flexible Joint for Steam and Water-pipes.

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The chief novelty in this swivel joint is the manner in which thepacking of the joints is completely enclosed, thereby rendering themperfectly and permanently watertight.

1844. An Improvement in Blowing Fans and their Bearings.

The principle on which Blowing Fans act, and to which they owe theirefficiency, consists in their communicating Centrifugal action to theair within them.

In order to obtain the maximum force of blast, with the minimumexpenditure of power, it is requisite so to form the outside rim of theFan-case as that each compartment formed by the space between the endsof the blades of the Fan shall in its course of rotation possess anequal facility of exit for the passage of the air it is discharging.Thus, in a Fan with six blades, the space between the top of the bladesand the case of the Fan should increase in area in the progressiveratios of 1-2-3-4-5-6.

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If a Fan be constructed on this common-sense principle, we shall securethe maximum of blast from the minimum of driving power. And not only so;but the humming sound--so disagreeable an accompaniment to the actionof the Fans (being caused by the successive sudden escape of the airfrom each compartment as it comes opposite the space where it candischarge its confined block of air)--will be avoided. When the outercase of a Fan is formed on the expanding or spiral principle,as above described, all these important advantages will attend its use.As the inward current of air rushes in at the circular openings on eachside of the Fan-case, and would thus oppose each other if there was afree communication between them, this is effectually obviated byforming the rotating portion of the fan by a disc of iron plate,which prevents the opposite in-rushing currents from interfering witheach other, and at the same time supplies a most substantial means offastening the blades, as they are conveniently riveted to this centraldisc. On the whole, this arrangement of machinery supplies a mosteffective "Noiseless Blowing Fan."

1845. A direct Action "Suction" Fan for the Ventilation of Coal-Mines.

The frequency of disastrous colliery explosions induced me to give myattention to an improved method for ventilating coal mines.The practice then was to employ a furnace, placed at the bottom of theupcast shaft of the coal-pit, to produce the necessary ventilation.This practice was highly riskful. It was dangerous as well asineffective. It was also liable to total destruction when an explosionoccurred, and the means of ventilation were thus lost when it was mosturgently required. The ventilation of mines by a current of air forcedby a Fan into the workings, had been proposed by a German named GeorgeAgricola, as far back as 1621. The arrangement is found figured in hiswork entitled De Re Metalicat, p. 162. But in all cases in which thissystem of forcing air through the workings and passages of a mine hasbeen tried, it has invariably been found unsuccessful as a means ofventilation.

As all rotative Blowing Fans draw in the air at their centres,and expel it at their circumference, it occurred to me that if we wereto make a communication between the upcast shaft of the mine and thecentre or suctional part of the Fan closing the top of the upcastshaft, a Fan so arranged would draw out the foul air from the mine,and allow the fresh air to descend by the downcast shaft,and so traverse the workings. And as a Suction Fan so placed would beon the surface of the ground, and quite out of the way of any risk ofinjury--being open to view and inspection at all times--we shouldthus have an effective and trustworthy means for thorough ventilation.

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Having communicated the design for my Direct Action Suction Fan forcoal-pit ventilation to the Earl Fitzwilliam, through his agentMr. Hartop, in 1850, his lordship was so much pleased with it that Ireceived an order for one of 14 feet diameter, for the purpose ofventilating; one of his largest coalpits. I arranged the steam-enginewhich gave motion to the large Fan, so as to be a part of it;and by placing the crank of the engine on the end of the Fan-shaft,the engine transferred its power to it in the most simple and directmanner. The high satisfaction which this Ventilating Fan gave to theEarl and to all connected with his coal-mines, led to my receivingorders for several of them.

I took out no patent for the invention, but sent drawings anddescriptions to all whom I knew to be interested in coalmine ventilation.I read a paper on the subject, and exhibited the necessary drawings, atthe meeting of the British Association at Ipswich in 1851. These wereafterwards published in the Mining Journal. The consequence is thatmany of my Suction Ventilating Fans are now in successful action athome and abroad.

1845. An improvement in the Links of Chain Cables.

1845. An Improved Method of Welding Iron.

One of the most important processes in connection with the productionof the details of machinery, and other purposes in which malleable ironis employed, is that termed welding, namely, when more or less complexforms are, so to speak, "built up" by the union of suitable portions ofmalleable iron united and incorporated with each other in the processof welding. This consists in heating the parts which we desire to uniteto a white heat in a smith's forge fire, or in an air furnace, by meansof which that peculiar adhesive "wax-like" capability; of stickingtogether is induced,--so that when the several parts are forciblypressed into close contact by blows of a hammer, their union isrendered perfect.

But as the intense degree of heat which is requisite to induce thisadhesive quality is accompanied by the production of a molten oxide ofiron that clings tenaciously to the white-hot surfaces of the iron,the union will not be complete unless every particle of the adhesingmolten scoriae is thoroughly discharged and driven out from between thesurfaces we desire to unite by welding. If by any want of due care onthe part of the smith, the surfaces be concave or have hollows in them,the scoriae will be sure to lurk in the recesses, and result in adefective welding of a most treacherous nature. Though the exterior maydisplay no evidence of the existence of this fertile cause of failure,yet some undue or unexpected strain will rend and disclose the shut-upscoriae, and probably end in some fatal break-down. The annexed figureswill perhaps serve to render my remarks on this truly important subjectmore clear to the reader.

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Fig.1 represents an imperfectly prepared surface of two pieces ofmalleable iron about to be welded. The result of their concavity ofform is that the scoriae are almost certain to be shut up in the hollowpart,--as the pieces will unite first at the edges and thus includethe scoriae, which no amount of subsequent hammering will everdislodge. They will remain lurking between, as seen in Fig.2. Happily,the means of obviating all such treacherous risks are as simple as theyare thoroughly effective. All that has to be done to render theiroccurrence next to impossible is to give to the surfaces we desire tounite by welding a convex form as represented in Fig. 3; the result ofwhich is that we thus provide an open door for the scoriae to escapefrom between the surfaces,--as these unite first in the centre, asdue to the convex form, and then the union proceeds outwards, untilevery particle of scoriae is expelled, and the union is perfectlycompleted under the blows of the hammer or other compressing agency.Fig. 4 represents the final and perfect completion of the welding,which is effected by this common-sense and simple means,--that is,by giving the surfaces a convex form instead of a concave one.

When I was called by the Lords of the Admiralty in 1846 to serve on aCommittee, the object of which was to investigate the causes of failurein the wrought-iron smith work of the navy, many sad instances camebefore us of accidents which had been caused by defective welding,especially in the vitally important articles of Anchors and Chain Cables.In the case of the occasional failure of chain cables, the cause wasgenerally assigned to defective material; but circumstances led me tothe conclusion that it was a question of workmanship or maltreatment ofwhat I knew to be of excellent material. I therefore instituted aseries of experiments which yielded conclusive evidence upon thesubject; and which proved that defective welding was the main and chiefcause of failure. In order to prove this, several apparently excellentcables were, by the aid of "the proving machine," pulled to pieces,link by link, and a careful record was kept of the nature of thefracture. The result was, that out of every 100 links pulled asunder80 cases clearly exhibited defective welding; while only 20 were brokenthrough the clear sound metal. This yielded a very important lesson tothose specially concerned.

1845. Introduction of the V Anvil.

In connection with my Steam Hammer, when employed in forging greatcylindrical shafts, I introduced what I termed my V anvil.Its employment has most importantly contributed to secure perfectsoundness in such class of forgings.

In the old system of forging cylindrical shafts, the bar was placedupon a flat-faced anvil. The effect of each blow of the hammer upon thework was to knock the shaft into an oval form (see Fig. 1); and theinevitable result of a succession of such blows was destruction of thesoundness of the centre or axis of the shaft.

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In order to remedy this grave defect, arising from the employment of aflat-faced anvil, I introduced my V anvil face (see Fig. 2), the effectof which was, that the dispersive action of the blow of the hammer waschanged into a converging action, which ensured the perfect soundnessof the work; while the V or fork-like form of the angle face kept thework steadily under the centre of the hammer, allowing the scale orscoriae to fall into the apex or bottom of the V, which thus passedaway, leaving the faces of the angle quite clear.

This simple and common-sense improvement was eagerly and generallyadopted, and has been productive of most satisfactory and importantresults.

1847. A Spherical-seated Direct-weighted Safety Valve.

Having been on several occasions called to investigate the causes ofsteam boiler explosions, my attention was naturally directed to thecondition of the Safety Valve. I found the construction of them in manycases to be defective in principle as well as in mechanical details;resulting chiefly from the employment of a conical form in the valve,which necessitated the use of a guide spindle to enable it to keep incorrect relative position to its corresponding conical seat, as seen atA in Fig. 1. As this guide spindle is always liable to be clogged withthe muddy deposit from the boiling water, which yields a very adhesiveencrustation, the result is a very riskful tendency to impede the freeaction of the Safety Valve, and thereby prevent its serving itspurpose.